Hydraulic demolition, also known as hydro-demolition, is a well-known art practiced by forcing an erosive material, generally a liquid such as water, through nozzles at sufficiently high pressure to produce a jet stream that disintegrates the materials of which buildings and structures are made thereby deconstructing the structural surface.
The term “structural surface” as used herein includes vertical walls, angled walls, curved walls, and any type of structural surface regardless of orientation or function that is amenable to having an opening cut therein by the apparatus and method disclosed below.
The terms “cut,” “cutting,” and “deconstructing” are used interchangeably herein to refer to the use of hydro-demolition technology to remove constituent material from a structural surface.
“Work-face” is used herein to refer to the area of a structural surface that is to be deconstructed.
The noun “opening” is used herein to refer to a hole that is cut into a structural surface, including a hole that does not completely penetrate the surface. The term “sides” when used without a modifier refers to the interior surfaces of such an opening, including the top, bottom, and lateral sides of the interior of the opening.
Hydro-demolition technology is often employed to cut openings in walls and other substantially vertical surfaces, and a number of hydro-demolition machines and techniques have been developed for these purposes.
In the art is it is well known to mount hydro-demolition devices on vehicles or platforms that are positioned on the ground. Generally, a lift-mechanism must be provided that is mounted on the ground, either directly or on a platform, and raises the cutting nozzles to the appropriate height to reach the work-face. This approach in which hydro-demolition equipment is supported by the ground is referred to herein as “bottom-up” hydro-demolition.
There are at least two significant problems with such a bottom-up approach to deconstructing structures with hydro-demolition equipment. First, it is necessary to have the machinery and, possibly, workmen, beneath the work-face. Because debris, eroded material, and water all fall downwards from the work-face under the force of gravity, the machinery and people working below the work-face can become soaked, coated with debris, and/or injured by the falling materials. The second significant problem is that there are limits as to how high such hydro-demolition devices can lift the nozzles. When working with very tall structures, a bottom-up approach to hydro-demolition is often not possible because the work-face is at a height that a cherry-picker or other lift-means cannot reach, or if they can, the resulting high center of gravity renders the equipment so unstable as to cause a hazard to workers.
For instance, in the field of nuclear reactors it is periodically necessary to deconstruct large areas from the reactor walls in order to make repairs to the walls or to structures embedded within the walls, such as tensioning tendons. As dozens of nuclear reactors approach and pass their life expectancy, it is also becoming commonplace to remove large pieces of equipment such as generators from the interior of the reactor for maintenance or replacement. In order to do this, it is often more economical to cut an opening in the wall of the reactor and remove the equipment through the opening rather than disassemble the equipment and take it out piece by piece through an existing “door,” so to speak. Given the thickness and structural complexity of reactor walls, and given the substantial heights above the ground at which the openings have to be cut, deconstructing such large structures presents formidable challenges that cannot be overcome effectively with existing hydro-demolition technology.
Complicating these problems is the fact that the structural surfaces of reactors are often three or more feet thick. Thus, the cutting nozzle must be able to advance a number of feet into an opening that may be hundreds of feet off of the ground.
Conventional “cherry-picker” and crane type devices do not suffice for these jobs; besides, they are dangerous because they require workers to be at or near the base of the wall while it is being deconstructed.
The present invention resolves the problem of how to carry out hydro-demolition deconstruction on very tall structural surfaces such as the walls of large nuclear reactors and tall buildings. In short, we have discovered a method and device for effectuating a top-down approach using a rigid support frame that obviates many problems that are unavoidable when working from the ground up. The device can be successfully employed and the method successfully practiced on structural surfaces of virtually any height.